Remove PRE_COMMIT_SECTOR_BATCH_MAX_SIZE and other gas-limited parameters

[jennijuju]

related to filecoin-project/lotus#10612

tl'dr: with FVM the execution gas are now properly accounted, and if the FVM gas accounting changes, the max value of how many msg can fit in one block may change.

Its better to remove thee limit from actors and have clients to perform gas estimation and properly aggregate sectors for users accordingly

[anorth]

There are other parameters that can be removed too, e.g. around Window PoSt.

• DECLARATIONS_MAX